This invention relates generally to the provision of industrial gas to a use point which requires a relatively small quantity and/or intermittent provision of the industrial gas.
The economical provision of industrial gas to a use point which uses a relatively small amount of such gas has a number of factors with which to contend. The cost of the gas is a relatively small portion of the total cost of the product after it is delivered to the use point. The gas product is provided from high pressure cylinders which come in various sizes or capacities. The high pressure cylinders are relatively heavy and contain only a small volume of gas. Transportation of these cylinders is not inexpensive, and requires a fair amount of labor to move them from the central production plant to the point of use. The cylinders must be positioned and hooked up to a distribution manifold, requiring additional labor. Floor space is required for cylindersxe2x80x94both full and empty ones. The empty cylinders must be returned to the central production plant to be refilled. A more efficient and economical method is desirable to supply the use point with product without involving this labor-intensive system using heavy, low pay-load cylinders.
Accordingly it is an object of this invention to provide an improved system for providing industrial gas to a use point.
It is another object of this invention to provide an improved system for providing industrial gas to a use point which uses a relatively small amount of such gas.
The above and other objects, which will become apparent to those skilled in the art upon a reading of this disclosure, are attained by the present invention, one aspect of which is:
A method for providing industrial gas product to a use point comprising:
(A) passing a gaseous industrial gas containing feed stream to an industrial gas generator, and producing gaseous industrial gas product in the industrial gas generator;
(B) generating a cold working gas, warming the cold working gas by indirect heat exchange with gaseous industrial gas product to liquefy gaseous industrial gas product, and storing the liquefied industrial gas product in a storage vessel; and
(C) providing industrial gas product from the storage vessel to the use point.
Another aspect of the invention is:
Apparatus for providing industrial gas product to a use point comprising:
(A) an industrial gas generator, a storage vessel, means for passing industrial gas containing feed to the industrial gas generator, and means for passing industrial gas product from the industrial gas generator to the storage vessel;
(B) a refrigeration system having a cold heat exchanger, said cold heat exchanger positioned to provide refrigeration to the industrial gas product; and
(C) an industrial gas use point and means for providing industrial gas product from the storage vessel to the industrial gas use point.
As used herein the term xe2x80x9cregeneratorxe2x80x9d means a thermal device in the form of porous distributed mass, such as spheres, stacked screens, perforated metal sheets and the like, with good thermal capacity to cool incoming warm gas and warm returning cold gas via direct heat transfer with the porous distributed mass.
As used herein the term xe2x80x9cpulse tube refrigeratorxe2x80x9d means a refrigerator device to produce low temperature refrigeration using suitable components including a pulse generator.
As used herein the term xe2x80x9corificexe2x80x9d means a gas flow restricting device placed between the warm end of the pulse tube expander and a reservoir in a pulse tube refrigerator.
As used herein the term xe2x80x9cpressure wavexe2x80x9d means a mass of gas that goes through sequentially high and low pressure levels in a cyclic manner.
As used herein the term xe2x80x9cindustrial gas generatorxe2x80x9d means apparatus which receives a gaseous industrial gas containing feed stream and produces a gaseous industrial gas product which has a higher concentration of the industrial gas than that of the feed stream.
As used herein the term xe2x80x9cworking gasxe2x80x9d means a gas used in a pulse tube refrigerator to produce refrigeration by going through cyclic pressure fluctuations. The working gas could be used in a closed cycle pulse tube system wherein the working gas could be helium, or in an open cycle pulse tube system wherein the working gas could be feed, e.g. air, product or waste gas from the industrial gas generator.